Silicon and other semiconductor wafers used in semiconductor devices, as well as solar wafers used in solar devices, are generally prepared from an ingot. The typical ingot has a generally cylindrical shape, but is not a perfect cylinder. Once the ingot has been grown, the ingot is cut to have a desired cross-sectional shape (e.g., a pseudo-square). Typically, the ingot is mounted on a mounting block to carry out the cutting operation. In order to maximize the usable volume of the ingot and minimize the size of the ingot needed to cut the desired cross-sectional shape, a predetermined centerline of the ingot should be aligned with the center of a mounting block, such that when the ingot is placed in a cutting assembly, the axis along which the ingot is cut is substantially aligned with the predetermined centerline of the ingot. Once mounted, the axis defined by the center of mounting block should be substantially the same as the axis along which the ingot is cut during the cutting procedures. Thus, the predetermined centerline of the ingot should be aligned with the center of a mounting block to the extent possible.
Conventionally, the semiconductor ingot is aligned with the center of the mounting block by use of centering plates having a “V”-shaped notch, also known as “V”-block halves. “V”-block halves are disposed on opposite sides of the ingot, and are attached to a threaded screw such that the centering plates can be closed around the ingot by rotation of the threaded screw. By closing the “V”-block halves around the ingot, the “V”-shaped notches engage the outer surface of the ingot, thereby adjusting the position of the ingot with respect to a mounting block. Once the ingot is aligned, adhesive is applied to a vertically positioned mounting block, and the ingot is adhered to the mounting block. The “V”-block halves determine the centerline of the ingot to be aligned with the mounting block, and do not permit alignment of a predetermined centerline.
This conventional method has several drawbacks. Because of imperfections in the ingot's shape, use of the “V”-block halves may result in the ingot being off-center from its volume maximizing centerline, thus resulting in wasted material during the cutting procedure. This may be corrected or compensated for by shims. But attempts to correct by use of shims or the like are extremely time consuming, and often inaccurate because there is no reliable way for the operator to verify that the ingot is optimally positioned. Also, because the mounting block is disposed vertically in close proximity to the ingot, the operator has little room to apply adhesive to the mounting block, thus making the process difficult. Accordingly, a need exists for a better system or method for centering and aligning an ingot with a mounting block.
This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.